1. Field
The invention relates to a switching valve for the transmission of fluids, in particular to the filling of gas tanks.
2. Description of the Related Art
Transmitting systems with such switching valves achieve a safe transmission of a fluid from a pressure source to a gas tank, for example in a fuelling system. Therein the simple operability and safety against contamination is of particular importance. Thus, U.S. Pat. No. 6,769,450 describes a valve system in which possible contamination from back flowing gas is prevented by a check valve such that residual quantities in the valve system are discharged by a vent valve in a controlled manner.
Further, WO 98/05898 of the Applicants describes a switching valve in the embodiment of a quick coupling, wherein a housing with a fluid inlet and a fluid outlet as well as several valves are provided in order to ensure a safe seal. These valves are controlled in a certain predetermined order by means of a control lever after connecting the quick coupling, whereby first the outlet valve will be opened, then the collets are closed with further movement of the control lever and finally the inlet valve is opened. Here, the control lever is an eccentric shaft with a sliding sleeve for actuating of the collets engaged with a sealing piston, which also releases the fluid inlet after complete coupling of the quick-connection. Further, a vent valve is provided for enabling pressure equalization before removing the quick-connect coupler even with high pressures without the risk of a backstroke. When closing the valves the exhaust valve works in type of a check valve. Although a safe connection is provided in this way, this coupling still has relative high manufacturing expenditure, in particular by the manual operation via the eccentric shaft.
Thus, the object of the invention is to provide a switching valve of the initially mentioned type that has a compact structure and enables simple handling as well as preventing contamination or a fluid reflux by controlled venting.